---
title: "Reference: handleWorkflowStream() | AI SDK"
description: API reference for handleWorkflowStream(), a framework-agnostic handler for streaming workflow execution in AI SDK-compatible format.
---

import PropertiesTable from "@site/src/components/PropertiesTable";

# handleWorkflowStream()

Framework-agnostic handler for streaming workflow execution in AI SDK-compatible format. Use this function directly when you need to handle workflow streaming outside Hono or Mastra's own [apiRoutes](/docs/v1/server-db/custom-api-routes) feature. 

`handleWorkflowStream()` returns a `ReadableStream` that you can wrap with [`createUIMessageStreamResponse()`](https://ai-sdk.dev/docs/reference/ai-sdk-ui/create-ui-message-stream-response).

Use [`workflowRoute()`](/reference/v1/ai-sdk/workflow-route) if you want to create a workflow route inside a Mastra server.

:::tip Agent streaming in workflows

When a workflow step pipes an agent's stream to the workflow writer (e.g., `await response.fullStream.pipeTo(writer)`), the agent's text chunks and tool calls are forwarded to the UI stream in real time, even when the agent runs inside workflow steps.

See [Workflow Streaming](/docs/v1/streaming/workflow-streaming#streaming-agent-text-chunks-to-ui) for more details.

:::

## Usage example

Next.js App Router example:

```typescript title="app/api/workflow/route.ts" copy
import { handleWorkflowStream } from '@mastra/ai-sdk';
import { createUIMessageStreamResponse } from 'ai';
import { mastra } from '@/src/mastra';

export async function POST(req: Request) {
  const params = await req.json();
  const stream = await handleWorkflowStream({
    mastra,
    workflowId: 'weatherWorkflow',
    params,
  });
  return createUIMessageStreamResponse({ stream });
}
```

## Parameters

<PropertiesTable
  content={[
    {
      name: "mastra",
      type: "Mastra",
      description: "The Mastra instance containing registered workflows.",
      isOptional: false,
    },
    {
      name: "workflowId",
      type: "string",
      description: "The ID of the workflow to execute.",
      isOptional: false,
    },
    {
      name: "params",
      type: "WorkflowStreamHandlerParams",
      description: "Parameters for the workflow stream.",
      isOptional: false,
    },
    {
      name: "params.runId",
      type: "string",
      description: "Optional run ID for the workflow execution.",
      isOptional: true,
    },
    {
      name: "params.resourceId",
      type: "string",
      description: "Optional resource ID for the workflow run.",
      isOptional: true,
    },
    {
      name: "params.inputData",
      type: "Record<string, any>",
      description: "Input data for starting a new workflow execution.",
      isOptional: true,
    },
    {
      name: "params.resumeData",
      type: "Record<string, any>",
      description: "Data for resuming a suspended workflow execution.",
      isOptional: true,
    },
    {
      name: "params.requestContext",
      type: "RequestContext",
      description: "Request context to pass to the workflow execution.",
      isOptional: true,
    },
    {
      name: "params.tracingOptions",
      type: "TracingOptions",
      description: "Options for tracing and observability.",
      isOptional: true,
    },
    {
      name: "params.step",
      type: "string",
      description: "Specific step to target in the workflow.",
      isOptional: true,
    },
    {
      name: "includeTextStreamParts",
      type: "boolean",
      description: "Whether to include text stream parts in the output.",
      isOptional: true,
      defaultValue: "true",
    },
  ]}
/>